include/QtCore/qstringconverter_base.h

0001 // Copyright (C) 2022 The Qt Company Ltd.
0002 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
0003 // Qt-Security score:critical reason:data-parser
0004
0005 #ifndef QSTRINGCONVERTER_BASE_H
0006 #define QSTRINGCONVERTER_BASE_H
0007
0008 #if 0
0009 // QStringConverter(Base) class are handled in qstringconverter
0010 #pragma qt_sync_stop_processing
0011 #endif
0012
0013 #include <optional>
0014
0015 #include <QtCore/qglobal.h> // QT_{BEGIN,END}_NAMESPACE
0016 #include <QtCore/qflags.h> // Q_DECLARE_FLAGS
0017 #include <QtCore/qcontainerfwd.h>
0018 #include <QtCore/qstringfwd.h>
0019
0020 #include <cstring>
0021
0022 QT_BEGIN_NAMESPACE
0023
0024 class QByteArrayView;
0025 class QChar;
0026 class QByteArrayView;
0027 class QStringView;
0028
0029 #if QT_VERSION < QT_VERSION_CHECK(7, 0, 0) && !defined(Q_QDOC) && !defined(QT_BOOTSTRAPPED)
0030 class QStringConverterBase
0031 #else
0032 class QStringConverter
0033 #endif
0034 {
0035 public:
0036     enum class Flag {
0037         Default = 0,
0038         Stateless = 0x1,
0039         ConvertInvalidToNull = 0x2,
0040         WriteBom = 0x4,
0041         ConvertInitialBom = 0x8,
0042         UsesIcu = 0x10,
0043     };
0044     Q_DECLARE_FLAGS(Flags, Flag)
0045
0046     struct State {
0047         constexpr State(Flags f = Flag::Default) noexcept
0048             : flags(f), state_data{0, 0, 0, 0} {}
0049         ~State() { clear(); }
0050
0051         State(State &&other) noexcept
0052             : flags(other.flags),
0053               remainingChars(other.remainingChars),
0054               invalidChars(other.invalidChars),
0055               state_data{other.state_data[0], other.state_data[1],
0056                          other.state_data[2], other.state_data[3]},
0057               clearFn(other.clearFn)
0058         { other.clearFn = nullptr; }
0059         State &operator=(State &&other) noexcept
0060         {
0061             clear();
0062             flags = other.flags;
0063             remainingChars = other.remainingChars;
0064             invalidChars = other.invalidChars;
0065             std::memmove(state_data, other.state_data, sizeof state_data); // self-assignment-safe
0066             clearFn = other.clearFn;
0067             other.clearFn = nullptr;
0068             return *this;
0069         }
0070         Q_CORE_EXPORT void clear() noexcept;
0071         Q_CORE_EXPORT void reset() noexcept;
0072
0073         Flags flags;
0074         int internalState = 0;
0075         qsizetype remainingChars = 0;
0076         qsizetype invalidChars = 0;
0077
0078         union {
0079             uint state_data[4];
0080             void *d[2];
0081         };
0082         using ClearDataFn = void (*)(State *) noexcept;
0083         ClearDataFn clearFn = nullptr;
0084     private:
0085         Q_DISABLE_COPY(State)
0086     };
0087
0088 #if QT_VERSION < QT_VERSION_CHECK(7, 0, 0) && !defined(Q_QDOC) && !defined(QT_BOOTSTRAPPED)
0089 protected:
0090     QStringConverterBase() = default;
0091     ~QStringConverterBase() = default;
0092     QStringConverterBase(QStringConverterBase &&) = default;
0093     QStringConverterBase &operator=(QStringConverterBase &&) = default;
0094 };
0095
0096 class QStringConverter : public QStringConverterBase
0097 {
0098 public:
0099 #endif // Qt 6 compat for QStringConverterBase
0100
0101     enum Encoding {
0102         Utf8,
0103 #ifndef QT_BOOTSTRAPPED
0104         Utf16,
0105         Utf16LE,
0106         Utf16BE,
0107         Utf32,
0108         Utf32LE,
0109         Utf32BE,
0110 #endif
0111         Latin1,
0112         System,
0113         LastEncoding = System
0114     };
0115
0116 protected:
0117
0118     struct Interface
0119     {
0120         using DecoderFn = QChar * (*)(QChar *out, QByteArrayView in, State *state);
0121         using LengthFn = qsizetype (*)(qsizetype inLength);
0122         using EncoderFn = char * (*)(char *out, QStringView in, State *state);
0123         const char *name = nullptr;
0124         DecoderFn toUtf16 = nullptr;
0125         LengthFn toUtf16Len = nullptr;
0126         EncoderFn fromUtf16 = nullptr;
0127         LengthFn fromUtf16Len = nullptr;
0128     };
0129
0130     constexpr QStringConverter() noexcept
0131         : iface(nullptr)
0132     {}
0133     constexpr explicit QStringConverter(Encoding encoding, Flags f)
0134         : iface(&encodingInterfaces[qsizetype(encoding)]), state(f)
0135     {}
0136     constexpr explicit QStringConverter(const Interface *i) noexcept
0137         : iface(i)
0138     {}
0139 #if QT_CORE_REMOVED_SINCE(6, 8)
0140     Q_CORE_EXPORT explicit QStringConverter(const char *name, Flags f);
0141 #endif
0142     Q_CORE_EXPORT explicit QStringConverter(QAnyStringView name, Flags f);
0143
0144
0145     ~QStringConverter() = default;
0146
0147 public:
0148     QStringConverter(QStringConverter &&) = default;
0149     QStringConverter &operator=(QStringConverter &&) = default;
0150
0151     bool isValid() const noexcept { return iface != nullptr; }
0152
0153     void resetState() noexcept
0154     {
0155         state.reset();
0156     }
0157     bool hasError() const noexcept { return state.invalidChars != 0; }
0158
0159     Q_CORE_EXPORT const char *name() const noexcept;
0160
0161 #if QT_CORE_REMOVED_SINCE(6, 8)
0162     Q_CORE_EXPORT static std::optional<Encoding> encodingForName(const char *name) noexcept;
0163 #endif
0164     Q_CORE_EXPORT static std::optional<Encoding> encodingForName(QAnyStringView name) noexcept;
0165     Q_DECL_PURE_FUNCTION Q_CORE_EXPORT static const char *nameForEncoding(Encoding e) noexcept;
0166     Q_CORE_EXPORT static std::optional<Encoding>
0167     encodingForData(QByteArrayView data, char16_t expectedFirstCharacter = 0) noexcept;
0168     Q_CORE_EXPORT static std::optional<Encoding> encodingForHtml(QByteArrayView data);
0169
0170     Q_CORE_EXPORT static QStringList availableCodecs();
0171
0172 protected:
0173     const Interface *iface;
0174     State state;
0175 private:
0176     Q_CORE_EXPORT static const Interface encodingInterfaces[Encoding::LastEncoding + 1];
0177 };
0178
0179 Q_DECLARE_OPERATORS_FOR_FLAGS(QStringConverter::Flags)
0180
0181 QT_END_NAMESPACE
0182
0183 #endif